I have a dynamic ip but it never seems to change...oh i cant use the method stated before because its assigned by a router....its hooked up through a dsl modem if that means anything
This is a common question, posted and answered on the forum a few times.
If your IP has a lease time associated with it, then it will be reassigned until that lease is expired. The lease is given to your MAC address.
Change the MAC address, you'll get a new lease, and a new IP with that lease.